*This paper represents the modified first part of a symposium on ""Investigation and treatment of Diarrhoeas in Childhood"", held at the meeting of the Medical Graduate Association, Witwatersrand University, on February 4, 1947. A brief outline is given of acute and chronic Nutr. Dis. in infants and young children, mainly from the point of view of aetiology, together with a short descriptionption of the methods of investigation employed.

The parasympathetic supply to the distal colon is descriptionbed. The suggested aetiological factor in megacolon is underfunctioning of the parasympathetic. Evidence of successful treatment of megacolon with parasympathetomimetic drugs is reviewed.